1. Field of the Invention
The present invention relates to a technique capable of acquiring dynamic state data of a work machine operating on site at a remote place.
2. Related Background of the Invention
Conventionally, there have been proposed and operated systems acquiring dynamic state data of a work machine operating on an operation site by making use of a communication line at a terminal in a maintenance center, an office or the like, being a remote place for convenience of a user of a work machine. The system disclosed in Japanese Patent No. 3011256 (Patent Document 1) being one of them is a system, in which, as shown in FIG. 5, data transmission and reception are performed between a management section 50 being a center, and each work machine 51 via a radio communication line, and the remote management section 50 acquires the dynamic state data of the work machine 51 on site. Further, this system is also adapted such that a terminal 52 of a client, who is the owner of the work machine 51, and a mobile terminal 53 of a serviceperson of a shop can access the work machine 51 to acquire the dynamic state data, as shown in FIG. 6.
Moreover, the Japanese Patent No. 3597772 (Patent Document 2) has proposed an anti-theft system causing a work machine to forcibly stop by transmitting a stop command of an engine from a management section when the work machine moves out of a predetermined region while applying the data transmission and reception of such a remote management system.
[Patent Document 1]
Japanese Patent No. 3011256 (paragraph 0028, FIG. 1, FIG. 7)
[Patent Document 2]
Japanese Patent No. 3597772 (paragraph 0008)
However, there is a problem in the system of the above Patent Document 1 that data cannot be received at a remote place while the engine of a work machine is at rest because a controller in charge of data transmission in each work machine basically has a mechanism of being interlocked with an engine key switch. Although the mechanism (referring to the paragraph 0028 in the Patent Document 1) is proposed, in which, by using a timer etc., transmission becomes possible while the timer is in operation by keeping the power supply for 5 to 10 minutes after the engine key switch is turned off, in most cases, the user desires the current position information and the latest dynamic state data even while the work machine is completely at rest, and such a recent desire cannot be satisfied at all.
Further, in the above Patent Document 2, there has taken place the case that when a work machine is stolen and taken out of a predetermined region with its engine at rest (for example, when it is conveyed on a truck etc.), the theft cannot be noticed by the management section side because no warning data is transmitted, and even when it is moved out of the predetermined region with engine operating, if the engine is stopped outside the predetermined region, the work machine cannot receive the stop command from the management section, and the function of anti-theft may not work.
Furthermore, in the system of the above Patent Document 1, as shown in FIG. 6, a client terminal 52 and also a serviceperson mobile terminal 53 can access the work machine 51 to acquire data, accordingly the work machine needs to prepare an authentication mechanism for plural connected parties, thereby making the processing complex and increasing a burden imposed by the security measures due to allowing plural accesses. Moreover, the burden of the running cost also increases in addition that the operation becomes unstable because of the complex mechanism of the system.